#defines for J5 as digital output

MIOS programming (C)
1

I am using J5 as digital output for a number of control signals. As these signals might be located on other pins in the future (depending on the hardware design), I would like to design my code such that the “pin mapping” can easily be reconfigured in the future.

So, instead of writing

PORTAbits.RA2 = 1;

I would prefer something like

Clk_LData = 1;

with Clk_LData being the name of the signal. I’m still no programmer, but would something like

/////////////////////////////////////////////////////////////////////////////
// Global definitions
/////////////////////////////////////////////////////////////////////////////

#define Clk_LData    PortAbits.RA1

in main.h do what I want? It compiles okay, but I am without hardware right now and cannot properly test it…

Thanks a lot, ilmenator

2

Works fine :slight_smile:

If you want to be sure - have a look in _output/*.asm and see what it makes in ASM. You should see like this:

#define Clk_LData PortAbits.RA1
Clk_LData = 1;

bsf PORTA,1
3

Great, thanks!

[edit: I had a typo in my code that gave a nice little error… hence a bit of confusion with some discussion in the chat :)]

4

So yes, as per the chat, the variables are case-sensitive, so we need “PORTAbits.RA1” :slight_smile:

Typos suck. I always forget the semicolons at the end of the line. I mean like aaaaaall the time, maybe one in every 50 lines I write… I dunno what’s wrong with my brain :smiley:

For those not in the chat:

[stryd_one] 12:13 am: illy hot tip for ya (i’ll put this in the thread too)

[stryd_one] 12:13 am: sdcpp is your friend

[stryd_one] 12:14 am: you can run the preprocessor standalone to see what your code outputs

[stryd_one] 12:14 am: and that’s what i’m about to do right now    

[stryd_one] 12:17 am: i create test.c:

#define Something PORTAbits.RA1
Something=1;

[stryd_one] 12:18 am: that’s all just the two lines.. you can do it with the whole file if you want, it doesn’t alter it [stryd_one] 12:19 am: then I run sdcpp (Small Device C PreProcessor…what handles the defines and #ifs and such) against the file:

C:\Temp>sdcpp test.c

1 “test.c”

1 “”

1 “”

1 “test.c”

PORTAbits.RA1=1;

C:\Temp>

[stryd_one] 12:19 am: works like a charm [stryd_one] 12:20 am: btw, you can output to a file like this:

sdcpp <yourfile.h> -o

[stryd_one] 12:21 am: sdcpp --help will show you a billion pages of options

HTH!